Verificationist
A verificationist is someone who adheres to the verification principle, a criterion for meaningfulness that requires a non-analytic, meaningful sentence to be either verifiable or falsifiable, though it was hotly disputed amongst verificationists whether this must be possible in practice or merely in principle. For example, a claim that the world came into existence a short time ago exactly as it is today (with misleading apparent traces of a longer past), would be judged meaningless by a verificationist because it is neither an analytic claim nor a verifiable claim. This criterion for meaning, per the verificationists, also had the effect of revealing a number of philosophic debates as meaningless since, per the verificationists, many philosophic debates are over the truth of unverifiable sentences. Notoriously, verificationism is often used to rule out as meaningless religious, metaphysical, and ethical sentences. However, not all verificationists have found sentences of these types to be unverifiable. The classical pragmatists, for example, saw verificationism as a guide for doing good work in religion, metaphysics, and ethics. Early Verificationists Empiricism All of the empiricists back to Locke could be treated as verificationists. The basic tenet of empiricism is that experience is our only source of knowledge and verificationism might be seen as simply a consequence of this tenet. Empiricists held that our ideas are either simple sense-perceptions or compilations and mixtures of these basic sense-perceptions. Reading this empiricist account, there does not seem to be any way for an idea to get into our heads without being connected to our perceptions and, thus, being connected to a means of verification. This leads empiricists like David Hume to reject philosophic positions about the existence of a God, a soul, or a self, since we are unable to point to the impression from which the idea of the thing is derived. Hume's Enquiry Concerning Human Understanding concludes with a rallying cry for the verificationist: When we run over libraries, persuaded of these principles, what havoc must we make? If we take in our hand any volume; of divinity or school metaphysics, for instance; let us ask, ''Does it contain any abstract reasoning concerning quantity or number? No. Does it contain any experimental reasoning concerning matter of fact and existence? No. Commit it then to the flames: for it can contain nothing but sophistry and illusion.Hume, D., ''Enquiries Concerning Human Understanding and Concerning the Principles of Morals Reprinted from 1777 edition, Third Edition, L. A. Selby-Bigge (ed.), Clarendon Press, Oxford, Sect. XII, Part III, p.165.''' The empiricists did not directly put forth a criterion of meaningfulness, but one could be seen as equivalent to the empiricists' claim that ideas not connected to experience are "empty". It is worth noting, however, that verificationism need not be a position about meaning. It is simply the position that unverifiable sentences are defective in some way that is similar to how false sentences and meaningless sentences are defective. Empiricists could therefore be read as asserting that unverifiable sentences are defective not because they are meaningless, but because they contain terms standing for ideas/concepts that we cannot possibly possess. Or, the empiricist could be read as asserting the semantic position that unverifiable sentences are meaningless preciesly because they contain terms standing for ideas/concepts that we cannot possibly possess. Positivism Auguste Comte put forth a semantic position not about the meaninglessness of unverifiable sentences, but rather about the pointlessness of considering them since they cannot be verified. This sort of rejection of unverifiable sentences as useless rather than meaningless would reoccur in the work of the classical pragmatists alongside their semantic verificationism. Comte was a rather extreme verificationist, rejecting everything we cannot have direct experience of. This included statements about the past, universal generalizations, as well as abstract objects like universals. Logical Positivism The verification principle is most associated with the logical positivist movement which had its roots in inter-war Vienna. Pragmatism Despite pre-dating logical positivism, pragmatism had very little influence on the logical positivists and most attention paid to verificationism has been directed to the positivists. This is mostly because logical positivism, unlike pragmatism, held the possibility of dismissing whole disciplines like metaphysics, morality, and ethics. The pragmatists differed from the logical positivists in their hospitality to areas of knowledge that the positivists hoped their principle would undermine. The pragmatists did not want to rule out metaphysics, religion, or ethics with the verification principle; they wanted to provide a standard for conducting good metaphysics, religion, and ethics. James coined the famous verificationist motto: "A difference that makes no difference is no difference". Falsificationism It is commonly believed that Karl Popper rejected the requirement that meaningful sentences be verifiable, demanding instead that they be falsifiable. However, Popper later claimed that his demand for falsifiability was not meant as a theory of meaning, but rather as a methodological norm for the sciences. Often, and to Popper's dismay, he is grouped as together with the verificationists rather than as a critic of verificationism. Post-Positivist Verificationists Quine and the Dogmas of Empiricism (1951) However that verificationists need not be logical positivists; Willard Van Orman Quine is a famous example of a verificationist who does not accept logical positivism, on grounds of semantic holism. He suggests that, for theoretical sentences as opposed to observation sentences, meaning is "infected by theory". That theoretical sentences are reducible to observation sentences is one of the ‘dogmas of empiricism’ he rejects as incompatible with semantic holism. Wittgenstein and the Private Language Argument (1953) An important topic in contemporary philosophy is Wittgenstein's argument against the possibility of a private language, which happens to be an example of later Wittgenstein's verificationism. Bas van Fraassen and Constructive Empiricism (1980) After the fall of logical positivism, verificationism and empiricism more generally lost many adherents. This trend was stopped and in large part reversed in 1980 with the publication of van Fraassen's ''The Scientific Image. Constructive empiricism states that scientific theories do not aim at truth, but to be empirically adequate and that their acceptance involves a belief only that they are empirically adequate. A theory is empirically adequate if and only if everything that it says about observable entities is "true" (or well-established). Constructive empiricism therefore rejects unverifiable positions not because they lack truth or meaning, but because they go beyond what is needed to be empirically adequate. See Also *Epistemic theories of truth :fi:Verifikationismi